Adding a router bubble for navigation

router/router.go

@@ -0,0 +1,71 @@
+package router
+
+import (
+	"github.com/charmbracelet/bubbles/key"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Screen represents a model with a particular binding to trigger it
+type Screen struct {
+	model   tea.Model
+	binding key.Binding
+}
+
+// Model stores different screens and the currently focused screens
+type Model struct {
+	screens []Screen
+	current int
+}
+
+// New creates a new empty Model
+func New() Model {
+	return Model{}
+}
+
+// NewWithScreens creates a new model with an array of Screen
+func NewWithScreens(screens []Screen) Model {
+	current := 0
+	return Model{
+		screens,
+		current,
+	}
+}
+
+func (m Model) updateCurrent(msg tea.Msg) (Model, tea.Cmd) {
+	if len(m.screens) <= m.current {
+		return m, nil
+	}
+	var cmd tea.Cmd
+	m.screens[m.current].model, cmd = m.screens[m.current].model.Update(msg)
+	return m, cmd
+}
+
+// AddScreen adds a new screen to the router
+func (m *Model) AddScreen(model tea.Model, binding key.Binding) {
+	m.screens = append(m.screens, Screen{model, binding})
+}
+
+// Init implements tea.Model
+func (Model) Init() tea.Cmd {
+	return nil
+}
+
+// Update implements tea.Model
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		for i, screen := range m.screens {
+			if key.Matches(msg, screen.binding) {
+				m.current = i
+				break
+			}
+		}
+	}
+
+	return m.updateCurrent(msg)
+}
+
+// View implements tea.Model
+func (m Model) View() string {
+	return m.screens[m.current].model.View()
+}